1. Field of the Invention
The invention is relates to a method for granulating and comminuting liquid slags, especially slags containing metal oxides such as, e.g., converter slags or refuse-incineration slags, mixtures of steel- and blast-furnace slags or non-ferrous metallurgic slags, e.g., Cu-- or Ni slags as well as to a device for carrying out this method.
2. Description of the Related Art
In an older development of the applicant (GM 94/98) a method already has been disclosed for granulating and comminuting liquid slags in which method pressurized water was driven into the slag melt, especially for the comminution of liquid blast-furnace slags, and the slag brought as a surface of the jet of pressurized water into a grinding chamber. With this method the direct conversion of the internal energy and especially of the perceptible heat of slag melts into grinding operations was directly utilized; however, the older suggestion, in which only water was driven in under high pressure, has a number of limitations with regard to the selection of the slags to be granulated and comminuted. The older method was basically suited primarily for the comminution of blast-furnace slags with only slight amounts of metals or metallic particles produced during the granulation. Blast-furnace slag to be granulated generally has a low amount of residual raw iron which is below 0.5% by weight if the method is carried out properly on the other hand, slags containing metal oxide or iron oxide such as converter slags have considerably greater amounts of residual raw iron and/or readily reducible iron oxides which, in conjunction with water as granulation medium, might bring pose a danger of exploding due to the formation of hydrogen gas. It was therefore suggested for this reason in the older method that the liquid slags be completely oxidized by introducing oxygen in order to increase safety and to saturate the liquid slags with gases in order to improve the communution action.